<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
<form action="<%=request.getContextPath()%>/a" method="get">
    <input type="submit" value="GET提交方式">
</form>
</div>
<div>
    <form action="<%=request.getContextPath()%>/a" method="post">
        <input type="submit" value="POST提交方式">
    </form>
</div>
</body>
</html>